Rotary transformer.



E. M. FRASER. ROTARY TRANSPORMER.

APPLICATION FILED APB.. 28. 1911.

` 1,052,717, Patented m1111913.

4 SHEETS-SHEET 1.

E. M. FRASER.

ROTARY TRANSFORMBR, APPLIGANON $111111) APR. 28, 1911.

1,052,7 17. Patented Feb. 11,1913.

` e 0 4 SHEETS-SHEET 2.

PatentedfFeb. 11, 1913.

4 SHEETS-SHEET 3.

E. M. FRASER.

ROTARY TRANSFORMBE.

APPLIGATION FILED APR. 28, 1911. 1 052,71 r7 latented Feb.,f11, 1913. 4 SHEETS-SHEET 4.

1mi/huwen:

lbroken away to show some of tl-,

nutren l. FRASER, OF YGNALRS, NEVI YORK.

ROTARY TBANSFQRE'ER.

' Specification of Letters ratent,

Application filed April 9.8, 1911. Serial No. 23,833.

Tall whom ,it may concern.'

Be it known that i, E'rnnnnnu'r lfd'. Faisan, ay citizen of the Dominionl of Canada, residing at Yonkers, county of lifestehesterand State of New York, have invented -a new and useful'improvementin Rotary Transformers, of which trie following' is a specification.

former'ffor obtaining` a direct our riable rvoltage of either polar' .Y introduction of ohmie resis ance into the circuityorusing switching or pole-ebanging ap] a ratas.

One of the objects of my invention is to provide a rotary transformer in which the Voltage and polarity of the current delivered can be varied by simultzuieously rotating` the auxiliary field magnets aud brusl es of the transformer in either' direct-ion aroundthe armature and eoinmutator, respectively, without. destructive sparking.

Another object is to provide a rotary transformer in which the main iield magnets are provided with eo-ils which neutralizcl the arinatui'e reaction.

Another object is to provide simple yet positiyemeans for simultaneously rotatino' the auxiliary field magnets and brushes or the transformer.

Another object, is to provide means for automatically limiting the rotation of the auxiliary field magnets and brushes to a predetermined amount.

lWiththe above and other objects in View, my yinvention Consists of the construction, arrangements and combinations of parts hereinafter described and claimed.

A structure 'embodying the features of my invention is illustrated in the accompanying drawings, forming a. part of this specifica.- tion, in which, i

Figure l is a` view in elevation of the transformer with part of the outer Casing broken away, and showing an enel View of the-controlling "mechanism en top ofthe transformer. Fig." 2 isa front seetionai View ofthe transformer, showing in fnli a side View of the cont-rolling` mechanism. Fig. 3 isa topyiew ofthecontroliing meehanism with v'part of' the housing,r casing` gears within. Fig. '-lis a central sectional vView of the controlling mechanism. 5 'is a sectional -i'iew of the transformer taken on the line i/y of Fig'. l. Fig. 6 is a wiring;l diagram.

in the tlrawings. similar letters of riefen ence refer to similar parts throughout the sfreral i'i'ews.

iieferring to the drawings, the rotary transformer comprises any standard form of. motor or dynamo frame eonsisting' of 'the base l0, the circular easing ll, and yoles l2, inclosinj"r the armature and the commutator lei, the armature and eommutator being mounted upon the shaft l5 which is suitably jourualed in the base l0 and the yolres l2. Secured to the casingA ll are the statioimry iield n ig'nets 16, preferably wound with shunt ud series coils (shown in Fig'. 6), and the stationary inter-pole magnets 1'! located between the field magnets 1G. The transformer may have any number of field magnets. but for purposes of illustration, 'i have shown a transformer provided with four stationary field magnets and a corre spending number of interpole magnets. i also provide stationary brushes 1S, secured to the yolres l2, so that the said brushes will bear upon the ('.oinmutator 1i. fis illustrated in the drawings, there are preferably one-half as many sets of stationary brushes as there are stationary poles, each set comprising positive and a negative brush.

The armature l?) is preferably made sutticicntly long to accommodate auxiliary field magnets it), which o also preferably wound with shunt and series coils (shoi'n in Fig'. These auxiliary .field magnets are secured to a rotatable member 20, comprising' a rinp; 2, a spider 22 and a bearing` ring- E23, which is so mounted Within the casing lt that it may be rotated in either direction Carrying with it the ring 21. As illustrated in the drawings, the auxiliary field magnets 19 are secured to the bearing ring the number of auxiliary eld magnets preferably Corresponding to the numbei' of stationary field magnets. Suitably secured to' theV ring' 2l are the auxiliary brushes 2st adapted to bear upon the comg mutato-i' ifi, for collecting the secondari` or *.'ariable '-:olt` e of the transformer.

In the preferred form of my invention, as illustrated in the drawings, I provide onehalf as many sets of auxiliary brushes as there are stationary poles, each set comprising a positive and a negative brush. The stationary and 'auxiliary brushes are arranged alternately. The positive and negative stationary brushes always maintain a fixed relation to each other, and the positive and negative movable brushes likewise maintain a fixed relation to each other. By reason of having positive and negative brushes in fixed relation to each other, the current distribution in the armature will always be symmetrical.

In' accordance with my invention, the auxliliary brushes and auxiliaryfield magnets are rotatable simultaneouslyin either direction with relation to the stationary brushes and stationary field magnets. This rotation may be accomplished by any suitable operating means, either mechanical or electrical. In the embodiment of my invention, herein shown, said means comprise the controlling mechanism secured to the top of the trans former, whereby the rotation of the armature shaft can be utilized to rotate theauxiliary field magnets and auxiliary brushes in either direction. As illustrated, said controlling mechanism comprises a shaft 25 on which is rotatably mounted a pair of gears 26, which are always in engagement with a meshing gear 27 secured to the end of the armature shaft 15. The gears 2G, which always rotate Vin opposite directions, are held against longitudinal displacement by being suitably' mounted in the housing or casing 28. Each of the gears 26 carries a friction plate 29, which is adapted to be thrown into frictional engagement with an accompanying friction disk 30, rigidly secured to the shaft 25. The engagement of either friction disk l30 with its respective friction plate 29 is accomplished by means of the handle 31 secured to -the bell-crank lever 32 which -is fulcrumed to the support 33 by the pin 34. The lever 32 is secured by the pin 35 to a thrust collar 36, which is loosely mounted upon the shaft 25 and retained between the two collars 37, 37, rigidly secured tothe shaft 25.

If the handle 31 be moved in thedirection of the dotted lines (Fig. 3), the lever 32 Will, through the medium of the thrust collar 36, cause the shaft 25 to move longitudinally in either direction, according to the direction of movement of the handle 31. [he longitudinal movement of the shaft 25 will cause'one or the other ofthe friction disks 30f'to engage its respective frictionl to which friction plate is in engagement with its respective friction disk.

In order that the rotation of the shaft 25 in either direction can be utilized for the rotation of the auxiliary brushes and auxiliary field magnets, I provide suitable mechanism intermediate of the rotatable ring 21 and the shaft 25. As illustrated in the drawings, said mechanism consists of the worm 3S in mesh with a` suitable worm gear 39, which is secured to the end of the shaft 40, carrying at its lower end a pinion L11 which engages the rack 42 secured to the rotatable ring 21. The worm 38 is suitably mounted upon the shaft 25 so as to permit of the longitudinal movement of the shaft therethrough, but to be rotated by the rotation of the shaft. The worm 38 and gear 39 are inclosed within a suitable housing 43.

The movement of the auxiliary field magnets and auxiliary brushes around the armature and commutator respectively in either direction can be controlled and stopped by bringing the handle 31 back to central position. By so doing, thc engagement of the friction disk 30 with its accompanying plate 29 is relieved, thereby preventing further rotation of the shaft 25.

As illustrated in the wiring diagram.

(Fig. 6) the numerals L19 and 50 indicate 95 the line wires or power circuit furnishing a direct current of substantially constant voltage, and the numerals 51 and 52 the wires of the secondary circuit. In series with the armature 13 through the stationary brushes 18 are the inter-pole magnet coils 53, ,which are shown connected to the line wires 49, 50. Inserted in this armature circuit is the starting rheostat 54:, the resistance of which is cut out during the normal running of the transformer. The stationary field magnets 16 are wound with twosets of coils 55 and 56`the coils 55 being shown.connected in shunt across thel line wires 49, and 50 by the conductors 57 and 58, while the other coils 56 are shown connected with the secondary circuit, as hereinafter explained. The auxiliary field magnets 19 are likewise wound with two sets of coils 5 9 and (iO-the coils 59 being shown in shunt across the line 49, 50, by the conductors 57 and 53, While the coils GO together with the coils 56 of the main field magnets are in series with the armature through the auxiliary brushes 24'and connected with the line wires 51,. 52 of the 4secondary circuit by the conductors 61, G2.

The main and auxiliary field magnets are, therefore, provided wit-h coils which are separately excited by a current of substantially constant voltage, and with coils which are excited by the secondary current.

In 6, the auxiliary brushes are shown midway between the stationary brushes, and the auxiliary field magnets on the central line of `the stationary field magnets. So poles; the series coils to oppose the armaplaced, the auxiliary field magnets and auxture reaction and to create a counter-elecviliary brushes are in the position ot Zero or troniotive torce to oppose the reactance minimum potential. lt the auxiliary lield voltage in the coils short circuited by the magnets be moved in one direction to the auxiliary brushes. y@

line of the edges` of their respective station- By using inter-pole magnets, the armaarylield magnets, the auxiliary iield magture reaction, or the tield created by the nets and the auxiliarybrushes 'ill then be armature Winding is neutralized. These inthe position of maximum potential. lt magnets also generate a counter-electro- 0 the auxiliary field magnets should be moved motive torce in opposition to the reactancc 75 in the other direction to the line of the voltage in the coils short circuited by the other edges of the stationary iield magnets, stationary brushes. Moreover, by providing the auxiliary field magnets and auxiliary the main iield magnets with series coils, eX- brushes Will be in the position ot maximum cited by the secondary current, the ield crepotential, 'but the secondary current will be ated by the armature winding due to the g@ of reversed polarity. secondary current is neutralized.

rlhe principle of operation of the rotary in the embodiment of my invention here- 'transtormer herein shown and described is in shown and described, if the auxiliary follows: llhen the brushes oit any dyfield magnets 19 move beyond the main 20 nan'io are moved away.- rom the neutral field magnets 16, they7 affect that part of g5 point or position of maximum voltage, the the armature not influenced by the main voltage generated lis less than the maXimagnetsnthat is, they generate an electromum, the iield strength remaining unmotive torce in the short-circuited coils. changed. The farther away from the neuln order, therefore, to prevent the auxiliary trai point the brushes are' moved the less magnets moving beyond the main magnets, 9@ .the voltage untila point is reached where l provide automatic means for limiting the the vvoltage is zero. lf the brushes are rotation or" the rotatable member 2O in kept'moving in the same direction the voltage either direction. Said automatic means gradually increases until the brushes again comprises a traveling nut la on the shaft 25,

se reach a. neutral point Where the'voltage is the nut lll being held against rotation by 95 once'more at the maximum, but the polarity the stem which engages the slot 4G in has now been reversed from what it was the extension et? ot the yoke l2. The shaft originally. The polarity will also be re- 25 is suitably threaded along the portion versed it the brushes are moved from the traversed by the nut lll, so that as-the lat-A neutral point in the opposite direction. lt ter moves along the shaft, due to its rota- 100 lis thus quite possible to obtain a variable `tion, it will move up against either thc voltage from any dynamo and also to rebumper 41S or the casing 43 thereby relievverse the polarity by simply moving the. ing the pressure oi the friction disk and brushes. The Igreatobjection to shitting plate which are in contact, and preventing the brushes on motors or dynamos used in further longitudinal and rotatable move 105 connection with constant potential is the ment of the shaft 25.' The movement ot excessive and destructive sparking. The the rotatable ring 2l, and consequently' the cause of sparking is-that when the armai'nove'i'ncnt of the auxiliary field magnets ture coils, short circuited by the brushes, can thus be limited to a pre-determined 45 move away from the neutral point they amount by 'regulating the amount of travel 110 enter a strong iield, thereby creating a dit'- of the nut flat. ference of potential and causing a current lt Will be obvious that numerous omisto lioW in these coils and through the sions, substitutions and changes may be I brushes, .When this current is broken as made in the various parts,` arrangements 5o the forward bar leaves the edge of the brush and Wiring herein shown and described, 1x5

there is a spark. rllhe self induction in the Without departing from my invention. armature coils also causes sparking, but not Having thus described my invcntin, as serious as the above-mentioned cause. what l claim as new, and desire to secure In the rotary transformer herein shown by Letters Patent, is: l

and described, I overcome sparking'by genl. ln a rotary transformer, the combina- 120 erating a counter-electromotive force in op tion with 'an armature, of a commutator position to the voltage being generated in therefor, a stationary field magnet, a mov the short-circuited coils. To this end, I able field magnet, and tivo indcpendent'sets provide the auxiliary lield magnets with i of brushes, one set of brushes being movable.

tWo sets oi. coils, as hereinbetore describedq 2. `In a rotary transformer, .the combina 12.5

' the shunt coils to create a counter-electiotion with an armature, of a commutator motive 'force in the 'portion of the arma- `therefor, stationary field magnets, a set of'v ture under `the auxiliary ,idoles in opposition stationary.. brushes, auxiliary iie'ldmagnets, to, theelectromotive` torce created in the and 'a vet lot auxiliary brushes, said field main portion of the armature by the main magnets and auxiliary brushes being` moviso tble simultaneously ina path around the arinature and commutator respectively in either direction.

3. In a rotary transformer, the combination with an armature, of a commutator therefor, stationary field magnets `having two "sets of coils, one set excited by a direct current of substantially constant voltage, the other set by a current of variable voltage of either polarity, rotatable field magnets, and two independent sets of brushes, one set of brushes being rotatable.

4. In a rotary transformer, the combination with an armature, of a commutator, positive and negative stationary brushes, positive and negative rotatable brushes, and stationary and rotatable field magnets, each field magnet having two sets of coils, one set of, coils being shunt-connected to a source of current supply of substantially constant. voltage, the other set being in series With the armature through said rotatable brushes.

5. In a rotary transformer, the combination with an armature, of a commutator, stationary'field magnets, interpole magnets, a set of stationarybrushes, a set of auxiliary brushes, and auxiliary field magnets, said auxiliary eld magnets and auxiliary brushes being movable simultaneously in a path around the armature and commutator, respectively, in either direction.

6. In a rotary transformer, the combination With an armature, of a commutator, stationary field magnets having shunt and series coils, a set of stationary brushes, a set o-f rotatable auxiliary brushes, interpole magnets, and rotatable auxiliary field magnets having shunt and series coils, the series coils of said auxiliary field magnets being in series with the series coils of said stationary eld magnets and With said auxiliary brushes.`

7. In a rot-ary transformer, the combination With an armature, of a commutator therefor, stationary field magnets, stationary positive and negative brushes, movable field magnets, and moyable positive and negative brushes, said movable field magnets having coils to neutralize the effect of the result-ant poles in said armature.

8. In a rotary tran-sformer, the combination with an armature, of a commutator therefor, positive and negative stationary brushes, positive andl negative movable brushes, stationary and movable field magnets, said magnets having coils to neutralize the armature reaction for every position of the movable brushes.

9. In agrotary transformer, the combina! tion With an armature, of a commutator therefor, stationary and movable field magnets, said movable field magnets having coils Which neutralize the armature reaction, and stationary and movable sets of brushes, the, brushes of each set arranged alternately around the armature and maintaining a fixed relation to each other.

10. In a rotary transformer, the combination with an armature, of a commutator, stationary and movable field magnets having coils to neutralize the armature reaction, and stationary and movable sets of brushes, the brushes of each set having a fixed relation to eachother whereby the current distribution in the armature is symmetrical.

11'. The combination with an armature, of a commutator therefor, stationary and movable field magnets, stationary and mov able sets of brushes, and means operated by said armature for simultaneously .moving said movable field magnets and brushes. ,k

l2. The combination with an armaturefof a commutator therefor, stationary field magnets, a set of stationary brushes, movable auxiliary field magnets, a set of movable auxiliary brushes, -means for simultaneously moving said auxiliary field magnets and auxiliary brushes around the armature and commutator respectively in either Idirection, and means for preventing said auxiliary field magnets from moving beyond said stationary field magnets.

18. The combination with an armature, of a commutator therefor, stationary field magnets, a set of stationary brushes, movable auxiliary field magnets, a set of movable auxiliary brushes, means for simultaneously moving said auxiliary field magnets `and auxiliary brushes around the armature and' commutator respectively in either direction, and means for controlling said movement.

14. The combination with an armature, of a commutator therefor, stationary field magnets, positive and negative stationary brushes, movable field magnets, positive and negative movable brushes, means for simultaneously moving said lastanentioned field magnets and brushes in either direction around the armature and commutator respectively, and means for limiting said movement to a pre-determined distance.

15. The combination with an armature,

of a commutator, stationary field magnets, positive and negative stationary brushes, movable field magnets, positive and negative movable brushes, means for simultaneously moving said last-mentioned field magnets and brushes around the armature and commutator respectively from substantially either position of maximum voltage to substantially the position of minimum voltage, or vice versa, and means cooperating with said first means. for cont-rolling said move ment.

16. The combination with an armature, of a commutator, stationary field magnets,`positive and vnegative stationary brushes,- movable field magnets, positive and negative movable brushes, means for simultaneously moving said last-mentionedA field magnets and brushes around the armature and commutator respectively from substantially either position of maximum voltage to substantially the position of minimum voltage, Orvicc versa, and means f'or autounltically stopping said movable field magnets and brushes at the maximum voltage position.

17. The combination with an arnlature, of a conunutator, stationary field niagnets, positive and negative stationary brushes, movable field magnets, positive and negative movable brushes, means for simultaneously moving said last-mentioned field magnets and brushes around the armature and commutator respectively from substantially either position of maximum voltage to substantially the position of minimum voltage, or vice versa, and means for automatically stopping said movable `field magnets and brushes at any desired point.

18. The combination with an armature, of a eommuta'tor therefor, brushes, compoundwound main field magnets, auxiliary eompound-wound field magnets, said auxiliary field magnets and said brushes being` mevable, means for simultaneously moving .said auxiliary field magnets and brushes in a path around the armature and.commutatorrespectively, and means for automatically limiting said movement.

lf). The combinationwith. an armature, ot a commutator therefor, Apositive and negative stationary brushes, positive and negative movable brushes, stationary and movable field magnets, each field magnet having two sets of coils, one set being shunt-connected to the source of current supply, the other set being in series with the arniature through said movable brushes, inter-pole magnet Coils in series with said armature through said stationary brushes, and means for simultaneously moving said movable field magnets and movable brushes around operated by said armature for simultaneously moving said movable field magnets and mo vable brushes around the armature and eommutator, respectively, in either direetion.

2l. The combination with an armature, of a conunutator therefor, positive and negative stationary brushes, positive and negative movable brushes, stationary and movable field magnets, each field magnet having two sets of' coils, one set being shunt-conneeted to the source at' current supply, the other set being in series with the armature thrmigh said m vable brushes, interpole magnetI coils in series .vitb said armature through said stationary brushes, means operated bythe armature for simultaneously moving said r-.ovahte field magnets and movable brushes around the armature Aand commutator respectively in either direct-ion, and means for automatically stopping said movable field magnets and brushes at any desired point.

In testimony whereof, I sign this speci-,

fication in the presence of two witnesses.

'ETHELBERT M. FRASER.

TWitnesses W. C. MauonsoN, D. HAROLD BUSH.A 

